From 25% of £30.44 subtract 50% of £13.50

25% means 0.25  (It also means 1/4.)
50% means 0.5 (It also means 1/2.)

0.25 of 30.44 = 7.61

0.5 of 13.50 = 6.75

From 7.61, subtract 6.75.

OK.  I did it.  The question just says "do it". It doesn't ask us what the result is.

If anybody asks you, you can do the subtraction, or just tell them it's 0.86 .
(Is that 86 pence?)

It’s hard to understand what you put.. can you show a picture ?